Heat-Capacity Anomaly from Four-Layer Liquid-Crystal Films.
01 January 1989
A high-sensitivity ac calorimeter system has been developed to investigate the temperature variation of the heat capacity from free-standing liquid-crystal films. We have observed clear evolution of the heat-capacity anomaly from films of the liquid-crystal compound 650BC as the films are reduced in thickness from 10 to 4 molecular layers near their bulk smectic-A-hexatic-B transition. Here 650BC refers to n-hexly- 4' -n-pentyloxybiphenyl-4-carboxylate. The 4-layer films show a single, sharp and cusp-like heat-capacity peak without thermal hysteresis.